Validity and Repeatability of Single-Sensor Loadsol Insoles during Landing

Abstract

Clinically feasible methods for quantifying landing kinetics could help identify patients at risk for secondary anterior cruciate ligament injuries. The purpose of this study was to evaluate the validity and between-day repeatability of the loadsol insole during a single-hop and bilateral stop-jump. Thirty healthy recreational athletes completed seven single-hops and seven stop-jumps while simultaneous loadsol (100 Hz) and force plate (1920 Hz) measurements were recorded. Peak impact force, loading rate, and impulse were computed for the dominant limb, and limb symmetry was calculated between limbs for each measure. All outcomes were compared between the loadsol and force plate using intraclass correlation coefficients (ICC) and Bland–Altman plots. Fifteen participants completed a second day of testing to assess between-day repeatability of the loadsol. Finally, an additional 14 participants completed the first day of testing only to assess the validity of the newest generation loadsol, which sampled at 200 Hz. At 100 Hz, validity ICC results were moderate to excellent (0.686–0.982), and repeatability ICC results were moderate to excellent (0.616–0.928). The 200 Hz loadsol demonstrated improved validity ICC (0.765–0.987). Bland–Altman plots revealed that the loadsol underestimated load measures. However, this bias was not observed for symmetry outcomes. The loadsol device is a valid and repeatable tool for evaluating kinetics during landing.

Load-Bearing Detection with Insole-Force Sensors Provides New Treatment Insights in Fragility Fractures of the Pelvis

“…Loadsol ® by Novel, was used in this study and has been shown to be a valid and reliable tool for wireless plantar force measurement in hopping, walking, and running [18]. Several studies were able to prove very similar results concerning the measurement with Loadsol ® compared to force plates [19,20].…”

Novel instrumented insole algorithm accurately approximates plantar flexor loading

“…Our findings demonstrate that simply calculating the weighted average of discretized plantar loads by sensor distances compare favorably with the motion capture (peak loading errors < 7%), the gold standard for biomechanical assessment during functional activities. While this type of instrumented insole has previously quantified loading magnitude and frequency [9][10][11], our study is the first to our knowledge to extend these plantar measurements to obtain motion capture quality measurements of joint level function.…”

Effect of Speed and Gradient on Plantar Force When Running on an AlterG® Treadmill.

“…Insole resolution was set at 5/10Newtons for a range of 0-2550N and a sample rate of 200 Hz using the Loadsol® App (version 1.5.10) on an Apple Ipad Pro 9.7 inch (Apple, Cupertino, USA). Here, we use the most recent generation of Loadsol® insoles with a sample rate of 200 Hz which demonstrated improved validity (ICC 0.76-0.98) over the previous generation of insoles (100 Hz) when compared with a force plate sampling at 1920 Hz [15]. Loadsol® insoles sampling at 200 Hz underestimate vertical force measurements in a reliable way when compared to force plates (95% limits of agreement 0.02 to 0.69BW) [15,12].…”

“…Wireless force sensing insoles are novel low-cost alternative to traditional embedded force plates for collection of clinical and research data. Loadsol® (Novel, Munich, Germany) insoles measure vertical ground reaction force experienced at the plantar surface of the foot (and contact times) during stance phase of gait, with excellent validity and reproducibility for walking, running [12,13], jumping, and hopping [14,15]. One advantage of wireless force sensing insoles is the ability to collect data on multiple steps when running in varied locations such as the eld of play or in reduced gravity treadmills.…”